CN1256666C - Dynamic download and execution of system services on wireless devices - Google Patents

Abstract

An applet requiring a virtual machine is downloaded to a wireless device. A software platform on the device determines that a virtual machine is used by the applet during execution. Without additional user interaction, the virtual machine is downloaded to the wireless device. This allows those applets requiring a virtual machine to be used with devices that don't have the virtual machine already installed. Further embodiments include the dynamic loading of a system service when an application is being loaded that uses the system service. A unique identifier associated with the system service may be used to determine if determine if the system service is loaded.

Description

Dynamic download and execution of system services on wireless devices

background

In general, system services including virtual machines, viewers, and plug-ins need to be installed on the device in order to be used by other objects or applications that require them. For example, a Java applet runs on a device that has a Java virtual machine loaded on it. Thus, a device attempting to execute a Java applet would have a Java virtual machine installed on the device. In general, since a virtual machine or other system service needs to be incorporated into the device it is said to execute on, it should be installed before attempting to download or execute an applet or other application that wishes to utilize a system service.

However, some devices, especially wireless devices, have constrained environments. Memory and processing are more scarce than on other larger computer systems, and memory includes both secondary and primary storage for active programs and data. Thus, it is advantageous to only download or install certain system services as needed, such as downloading virtual machines. Unfortunately, on these constrained devices, system services are required to be installed or loaded into memory and occupy valuable resources even when not being used. Furthermore, a user wishing to use an application on a system service-enabled device that does not yet have the application cannot do so because the system service has not yet been installed on the device.

Summary of Invention

The present invention overcomes the deficiencies in the art by providing a system and method in a device for dynamically downloading and installing system services as required by applications running on the device, wherein system services have virtual machines , viewfinder, plug-in, flash player, other executable content or data.

In one embodiment, the invention involves downloading system services onto a wireless device for use with an application to be downloaded. System services may be downloaded automatically without user intervention when downloading applications.

In yet another embodiment, the present invention also detects the presence of a virtual machine when the application is loaded into the memory of the device for execution, and loads and executes the virtual machine as needed, so the application may run in the virtual machine's Environment.

In accordance with the present invention, a method of receiving a virtual machine at a wireless device is provided. The method comprises the steps of:

sending a request to download an application on the wireless device;

a server sending the application and an associated reference to the wireless device in response to the request for the application, wherein the reference indicates that the application uses the virtual machine;

using the reference to determine whether the virtual machine is loaded on the wireless device; and

In the event that the virtual machine is not loaded on the wireless device, a request is sent to the server and the virtual machine is downloaded to the wireless device.

Brief description of attached drawings

Exemplary and preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, wherein like symbols designate like or corresponding parts throughout the several drawings. The nature, objects and advantages of the present invention will become more apparent to those skilled in the art upon consideration of the following detailed description when taken in conjunction with the accompanying drawings.

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate preferred embodiments of the invention and, together with the general description given above and the detailed description of the preferred embodiments given below, serve to explain the principles of the invention. In the attached picture:

Figure 1 illustrates an exemplary embodiment of an environment in which the present invention may be practiced;

Figure 2 illustrates the process involved in downloading an application using a system service consistent with an exemplary embodiment of the present invention; and

FIG. 3 illustrates the process of loading and executing a virtual machine installed on a wireless device in response to loading of an application that uses the virtual machine.

Description of Exemplary Embodiments

Figure 1 illustrates an exemplary embodiment of an environment in which the present invention may be practiced. In this embodiment, device 100 communicates with server 105 using wireless network 125 . Device 100 may be a wireless device that may transmit and/or receive data and/or voice. The wireless device 100 may request various pieces of information from the server, including applications 110 and system services 115, such as virtual machines 120 used by the wireless device.

Wireless device 110 may contain a processor and primary and secondary memory (not shown) for storing, loading and executing application programs 110 and system services 115 downloaded from a server. These applications 110 and system services 115 may also interact with a software platform located on the wireless device to simplify interfacing with the wireless device, such as by providing generic calls to device-specific resources. This software platform is a Binary Runtime Environment (Binary Runtime Environment) of Wireless (Wireless) ^TM (BREW ^TM ) software developed by Qualcomm (QUALCOMM) Corporation (San Diego, California).

Those skilled in the art can recognize that the structure of the wireless device 100 may also include other types of components (or not shown or specifically indicated). Such components include, but are not limited to: displays, speakers, microphones, and buttons that allow character and symbol entry. A wireless device may also include a battery, various storage mechanisms such as ROM, ROM, and flash memory, an operating system, and compilation components to help execute applications, system services, other executable code, and manage data on the device.

Although the system services and application programs described above are located on the server 105, those skilled in the art can understand that the application programs and software may not be physically located on the server. In this case, the server may request the wireless device's application and system services from other systems and then download the requested files, or it may transmit the request to another system for transferring the requested files directly to the wireless device .

As can be understood by those skilled in the art, Figure 1 is an exemplary environment of the present invention. Devices may include other types of systems, including wireless and non-wireless devices. In addition, devices may communicate with servers and other systems using a variety of network types and communication structures, including wireless and non-wireless, private and public, switched and non-switched, direct links, or any combination thereof.

Figure 2 illustrates the process involved in downloading an application that uses system services consistent with an exemplary embodiment of the present invention. A device, such as wireless device 100, requests an application from server 105 (step 200). The request may have been initiated because the user requested a particular application, such as a game, from the wireless device. A wireless device may be configured such that not all of the applications available to the user reside on the device itself, but only store a representation of those applications that the user has access to.

However, the request may be non-user initiated and may include tasks for system maintenance as well as tasks that do not involve direct user interaction. Additionally, requests may be for file types other than applications, including data, system services, or other information types.

The device then receives the application from the server and stores it (step 205). In one embodiment, the server sends the requested application to the device. However, as noted above, the application may not be physically located on the server; however, the server may receive the application and begin downloading the application to the device.

The device then checks the application to determine if the application uses system services (step 210). Applications may include references, or certain identifiers, that indicate system services used with the application. The reference may be included within the application, or be related to the application in some other way.

In one embodiment, the application program is a Java applet and requires a Java virtual machine (system service) to execute. A device may contain a software platform, such as Brew( ^TM) described above. The device determines, with the software platform, that the Java virtual machine is used by the applet by checking for any references by the applet to an object class indicative of a Java virtual machine. In one embodiment, each object class is represented by a unique 32-bit identifier, and this identifier can be used to determine which object class is referenced.

The device then determines whether the system service has been installed on the device (step 215). In one embodiment, this is done by checking an internal table listed in the Object Class installed on the device. Using the 32-bit identifier referenced by the downloaded application, check an internal table to determine whether the referenced object class is installed, or use the above example to determine whether the Java virtual machine is installed on the device.

If the system service is not installed, then follow the "No" branch down, and the system further downloads the system service (step 220). According to the above example, if the Java virtual machine used by the downloaded application is not installed in the device, the device makes a request to the server to download the Java virtual machine. Additionally, other system services may also be downloaded to the device if they are required.

Those skilled in the art will appreciate that downloading system services used by downloaded applications can be performed without user action. Aside from some possible transmission delay or indication, the user may be completely unaware that these downloads are taking place. However, it may be desirable to notify the user that additional downloads are taking place. This is an implementation option left to practice the invention.

Those skilled in the art will also understand that downloading of system services may be independent of whether an application has already been downloaded (ie, downloading of system services may be initiated by the application being installed at the factory or transferred to the device).

If the system service has been installed in step 210 or after it has been downloaded in step 220, the system service is available when executing the application. Those skilled in the art can understand that system services may be downloaded to the device but not loaded into the device for execution.

While the above description incorporates a device making a determination of whether a system service is needed and downloading the system service in response to a request from the device, the present invention also encompasses a process in which a server or other system makes a determination as to whether a system service is needed and Whether the system service has already been installed and the system service is downloaded.

FIG. 3 illustrates the process of loading and executing a virtual machine installed on a wireless device in response to loading an application program using the virtual machine. The process begins by selecting an application from those available for the wireless device (step 300). This selection may be performed by a user wishing to execute the application. However, selection may be performed by the device or in some other automatic manner without user intervention.

After the application is selected, the device loads the application into memory for execution (step 305). (Depending on the environment in which the application is executed, the loading of the application may be considered part of the execution of the application). During this loading phase, the loader (the component that loads the application for execution) requests virtual machine services (step 310). In one embodiment, the loader may perform this using an application programming interface (API) mechanism built into the software platform described above, using a unique class identifier to identify the virtual machine.

For example, the application program may be a Java applet that requires execution on the wireless device using a Java virtual machine. A loader that loads a Java applet on a device for execution may request Java virtual machine services by using the Brew ^(TM) API mechanism, which identifies the Java virtual machine with a unique identifier. In one embodiment, the identifier is a 32-bit class identifier.

The appliance then determines whether the virtual machine system service is loaded into memory (step 315). The device may do this by examining the object class loaded into memory. To track those system services, applications, executables, data, other loaded data types or object classes, it is best to use an identifier associated with each object class.

The appliance, specifically the Brew software platform in one embodiment, makes a determination as to whether the virtual machine requested by the loader is already in memory.

If the virtual machine has not been loaded into memory as determined in step 315, then the "no" branch is followed and the appliance loads the virtual machine (step 320). If the virtual machine has not already been installed on the wireless service, the virtual machine may be downloaded onto the wireless device from an external source, such as a server or other computer system that has access to the virtual machine software.

Depending on the device and operating platform and system service on which the invention is implemented, the system service may require additional execution or initiation steps after its loading. A system service, or virtual machine in this embodiment, should be in a state within the device that it can access to downloaded applications or possibly other processes when executed.

Following step 320 or if a determination is made at step 315 that a virtual machine has been loaded, the application runs in the virtual machine environment (step 325). Apps can now use system services downloaded for the app if the system service is not a virtual machine. In the Java virtual machine example, Java applets are executed in a Java virtual machine environment.

If the device includes a software platform, such as Brew ^™ software, to simplify the interface from the application to the wireless device, the virtual machine passes system service requests made by the application or virtual machine to the software platform (step 330).

It will be appreciated that while FIG. 3 discusses an application using a virtual machine during execution, this is for example purposes and that the scope of the invention contemplates other system services, other Dynamic loading of executable content and data.

in conclusion

The invention allows dynamic downloading and execution of system services on devices. In one embodiment, an applet requiring a virtual machine is downloaded to the wireless device. The software platform on the device determines that the virtual machine is used by the applet during execution. The virtual machine is downloaded to the wireless device without additional user interaction. This allows applets that require a virtual machine to be used with devices that don't already have a virtual machine installed.

Another embodiment of the present invention allows dynamic loading of system services, such as virtual machines, when loading applications that use the system services. In this embodiment, this is accomplished using a unique identifier associated with a system service that allows a device to determine whether a system service has been loaded.

The foregoing description of the implementation of the present invention has been presented for purposes of illustration and description. It is not exhaustive and does not limit the invention to the precise forms disclosed. With the above principles in mind, modifications and variations are possible and may be acquired when practicing the invention. For example, the described implementation includes software, but an embodiment of the invention may be implemented in a combination of hardware and software, or in hardware only. The present invention can be implemented with both object-oriented and non-object-oriented programming systems. In addition, although aspects of the present invention have been described as being stored in memory, those skilled in the art will understand that these aspects can also be stored on other types of computer-readable media, such as secondary storage devices, such as hard disks, floppy disks or CD-ROM; carrier waves from the Internet or other transmission media; or other forms of RAM or ROM. The scope of the invention is defined by the appended claims and their equivalents.

Claims (4)

1. a method that receives a virtual machine at the wireless device place is characterized in that, comprises the steps:

Send a request, require on described wireless device, to download an application program;

One server sends to described wireless device according to the request to described application program with quote relevant with of described application program, and wherein said quoting indicated described application program to use described virtual machine;

Quote to determine with described whether described virtual machine is loaded on the described wireless device; And

Under described virtual machine is not loaded into situation on the described wireless device, send one and ask described server, and described virtual machine download to described wireless device.

2. the method for claim 1 is characterized in that, also is included in described server place, receives the request to described application program.

3. the method for claim 1 is characterized in that, described application program is the java code, and described virtual machine is the java virtual machine.

4. the method for claim 1 is characterized in that, described application program is used described virtual machine when carrying out.

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